gls.hpp

/*
 This Source Code Form is subject to the terms of the Mozilla Public
 License, v. 2.0. If a copy of the MPL was not distributed with this
 file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
 
template <class DataPoint, class _NFilter, typename T>
    requires GLS_PARAM_REQUIREMENTS
inline FIT_RESULT GLSParam<DataPoint, _NFilter, T>::finalize()
{
    FIT_RESULT bResult = Base::finalize();
 
    if (bResult != UNDEFINED)
    {
        m_fitness = Scalar(1.) - Base::prattNorm2();
    }
 
    return bResult;
}
 
template <class DataPoint, class _NFilter, int DiffType, typename T>
    requires GLS_DER_REQUIREMENTS
typename GLSDer<DataPoint, _NFilter, DiffType, T>::ScalarArray GLSDer<DataPoint, _NFilter, DiffType, T>::dtau() const
{
    PONCA_MULTIARCH_STD_MATH(sqrt);
 
    Scalar prattNorm2  = Base::prattNorm2();
    Scalar prattNorm   = sqrt(prattNorm2);
    Scalar cfactor     = Scalar(.5) / prattNorm;
    ScalarArray dfield = Base::m_dUc;
    // Recall that tau is the field function at the evaluation point, we thus must take care about
    // its variation when differentiating in space:
    if (Base::isSpaceDer())
        dfield.template tail<DataPoint::Dim>() += Base::m_ul;
 
    return (dfield * prattNorm - Base::m_uc * cfactor * Base::dprattNorm2()) / prattNorm2;
}
 
template <class DataPoint, class _NFilter, int DiffType, typename T>
    requires GLS_DER_REQUIREMENTS
typename GLSDer<DataPoint, _NFilter, DiffType, T>::VectorArray GLSDer<DataPoint, _NFilter, DiffType, T>::deta() const
{
    return Base::dNormal();
}
 
template <class DataPoint, class _NFilter, int DiffType, typename T>
    requires GLS_DER_REQUIREMENTS
typename GLSDer<DataPoint, _NFilter, DiffType, T>::ScalarArray GLSDer<DataPoint, _NFilter, DiffType, T>::dkappa() const
{
    PONCA_MULTIARCH_STD_MATH(sqrt);
 
    Scalar prattNorm2 = Base::prattNorm2();
    Scalar prattNorm  = sqrt(prattNorm2);
    Scalar cfactor    = Scalar(.5) / prattNorm;
 
    return Scalar(2.) * (Base::m_dUq * prattNorm - Base::m_uq * cfactor * Base::dprattNorm2()) / prattNorm2;
}
 
template <class DataPoint, class _NFilter, int DiffType, typename T>
    requires GLS_DER_REQUIREMENTS
typename GLSDer<DataPoint, _NFilter, DiffType, T>::ScalarArray GLSDer<DataPoint, _NFilter, DiffType,
                                                                      T>::dtau_normalized() const
{
    return dtau();
}
 
template <class DataPoint, class _NFilter, int DiffType, typename T>
    requires GLS_DER_REQUIREMENTS
typename GLSDer<DataPoint, _NFilter, DiffType, T>::VectorArray GLSDer<DataPoint, _NFilter, DiffType,
                                                                      T>::deta_normalized() const
{
    return Base::getNeighborFilter().evalScale() * deta();
}
 
template <class DataPoint, class _NFilter, int DiffType, typename T>
    requires GLS_DER_REQUIREMENTS
typename GLSDer<DataPoint, _NFilter, DiffType, T>::ScalarArray GLSDer<DataPoint, _NFilter, DiffType,
                                                                      T>::dkappa_normalized() const
{
    return dkappa() * Base::getNeighborFilter().evalScale() * Base::getNeighborFilter().evalScale();
}
 
template <class DataPoint, class _NFilter, int DiffType, typename T>
    requires GLS_DER_REQUIREMENTS
typename GLSDer<DataPoint, _NFilter, DiffType, T>::Scalar GLSDer<DataPoint, _NFilter, DiffType, T>::geomVar(
    Scalar wtau, Scalar weta, Scalar wkappa) const
{
    static_assert(bool(DiffType & FitScaleDer), "Scale derivatives are required to compute Geometric Variation");
    Scalar dtau   = dtau_normalized().col(0)(0);
    Scalar deta   = deta_normalized().col(0).norm();
    Scalar dkappa = dkappa_normalized().col(0)(0);
 
    return wtau * dtau * dtau + weta * deta * deta + wkappa * dkappa * dkappa;
}